WASHINGTON--Nearly 30,000 airline passengers discovered in the past year that they were mistakenly placed on federal "terrorist" watch lists, a transportation security official said Tuesday.

Jim Kennedy, director of the Transportation Security Administration's redress office, revealed the errors at a quarterly meeting convened here by the U.S. Department of Homeland Security's Data Privacy and Integrity Advisory Committee.

Marcia Hofmann, staff counsel at the Electronic Privacy Information Center, said this appeared to be the first time such a large error has been admitted. "It was a novel figure to me," Hofmann said. "The figure shows that many more passengers than we've anticipated have encountered difficulty at airports. The watch list still has a long way to go before it does what it's supposed to do................